The present invention relates to a method for measuring the mass of a pulsating medium flowing in a flow cross section, in particular, for measuring the aspirated air mass of internal combustion engines. A method and an apparatus are already known in which the measuring signal corresponding to the mass of air aspirated by an internal combustion engine includes an error, which is based on the fact that the apparatus also ascertains the mass of the air flowing backward in the intake tube of the engine because of the pulsation.